I debated if I should put this on the monthly bench efforts, but thought maybe it could stand it's own thread....
I have 4 of the old Herters flat bottom coot decoys I got from John Livoti a few years back. I restle coated them and repainted them. I have since gotten another pr from John Bourbon, the newer, model 63 bodies.
View attachment IMG_1950[1].JPG
I prefer the old, smaller bodies with these heads. I want to round out my rig, and make up 8 more bodies, and need 6 more heads. Since I had a pr of heads not yet mounted, I thought I might try my hand at making a mold. A little reading, youtube watching, and questions, and I got started:
View attachment IMG_1929.JPG
I build a box with thin clear plastic from Home Depot. Because I had bought special, non-sulphur clay, I built up the area around the heads with corrugated plastic to take up space. It turns out, I likely had enough clay but oh well.
I filled the hole in decoy stems with hot glue and set them in the base. Worked the clay to the parting lines, and added registration dimples in the clay.
Release agent was sprayed into the cavity, and the Smooth-on Mold Star 30 was mixed and poured.
View attachment IMG_1936.JPG
After waiting the 6 hours of cure, I peeled open the box.
View attachment IMG_1937.JPG
And peeled off the mold half.
View attachment IMG_1938.JPG
After cleaning up the clay on the silicone mold half, I rebuilt the box and prepared for the other mold. Success!
View attachment IMG_1942.JPG
Today, I got to pour my first heads. I used Smooth-on Feather Lite, which is a 2 part Urethane casting resin, that is heavily filled. This material has a hardness of 58 Shore D, is machineable, supposed to be durable, and it floats. I the fill floats on the top and is quite hard. When you open the can it appears the material is fully cured. Once you break through the top half of each can, there is liquid below. After a good 10 minutes of mixing it all goes into solution.
View attachment IMG_1946.JPG
Mixed 1:1 by volume it has a pot life of about 8 minutes. Cure time is 2 hours.
View attachment IMG_1952.JPG
And finally I have the first heads out of the mold....
View attachment IMG_1953.JPG
I had calculated the volumes, but mixed a little extra to play it safe. After this first pour, I know my calculation was pretty spot on, and will not waste as much on subsequent pours.
I did get a little voiding at the base of the neck, that will easily be blended when I install the heads, but on the next pour I vibrated the mould after pouring to see if I might displace the bubbles? If these are the worst and all are the same, I am still pleased with this first molding attempt.
View attachment IMG_1954.JPG
I have 4 of the old Herters flat bottom coot decoys I got from John Livoti a few years back. I restle coated them and repainted them. I have since gotten another pr from John Bourbon, the newer, model 63 bodies.
View attachment IMG_1950[1].JPG
I prefer the old, smaller bodies with these heads. I want to round out my rig, and make up 8 more bodies, and need 6 more heads. Since I had a pr of heads not yet mounted, I thought I might try my hand at making a mold. A little reading, youtube watching, and questions, and I got started:
View attachment IMG_1929.JPG
I build a box with thin clear plastic from Home Depot. Because I had bought special, non-sulphur clay, I built up the area around the heads with corrugated plastic to take up space. It turns out, I likely had enough clay but oh well.
I filled the hole in decoy stems with hot glue and set them in the base. Worked the clay to the parting lines, and added registration dimples in the clay.
Release agent was sprayed into the cavity, and the Smooth-on Mold Star 30 was mixed and poured.
View attachment IMG_1936.JPG
After waiting the 6 hours of cure, I peeled open the box.
View attachment IMG_1937.JPG
And peeled off the mold half.
View attachment IMG_1938.JPG
After cleaning up the clay on the silicone mold half, I rebuilt the box and prepared for the other mold. Success!
View attachment IMG_1942.JPG
Today, I got to pour my first heads. I used Smooth-on Feather Lite, which is a 2 part Urethane casting resin, that is heavily filled. This material has a hardness of 58 Shore D, is machineable, supposed to be durable, and it floats. I the fill floats on the top and is quite hard. When you open the can it appears the material is fully cured. Once you break through the top half of each can, there is liquid below. After a good 10 minutes of mixing it all goes into solution.
View attachment IMG_1946.JPG
Mixed 1:1 by volume it has a pot life of about 8 minutes. Cure time is 2 hours.
View attachment IMG_1952.JPG
And finally I have the first heads out of the mold....
View attachment IMG_1953.JPG
I had calculated the volumes, but mixed a little extra to play it safe. After this first pour, I know my calculation was pretty spot on, and will not waste as much on subsequent pours.
I did get a little voiding at the base of the neck, that will easily be blended when I install the heads, but on the next pour I vibrated the mould after pouring to see if I might displace the bubbles? If these are the worst and all are the same, I am still pleased with this first molding attempt.
View attachment IMG_1954.JPG
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